opera -- RSA Signature Forgery

Details

VuXML ID

1fe734bf-4a06-11db-b48d-00508d6a62df

Discovery

2006-09-18

Entry

2006-09-22

Opera reports:

A specially crafted digital certificate can bypass Opera's
certificate signature verification. Forged certificates can
contain any false information the forger chooses, and Opera
will still present it as valid. Opera will not present any
warning dialogs in this case, and the security status will
be the highest possible (3). This defeats the protection
against "man in the middle", the attacks that SSL was
designed to prevent.

There is a flaw in OpenSSL's RSA signature verification
that affects digital certificates using 3 as the public
exponent. Some of the certificate issuers that are on
Opera's list of trusted signers have root certificates with
3 as the public exponent. The forged certificate can appear
to be signed by one of these.